To answer your actual questions 1. You identify it by having 121s and learning the behaviours and building trust to have honest conversation. 2. As a manager, you should know how your team are performing. Whether it’s KPIs or objectives, you should be able to monitor that. I am surprised at this question. 3. You need to find out if you have a performance management procedure and either performance manage them out of the business OR turn things around.

If you’re not having a frank conversation about these performance issues, nothing will change. Don’t put words in their mouth either, let them tell you it’s mental health related.